Control plate in a valve

ABSTRACT

A control plate for effecting superior shut-off in a proportional control valve comprises a moveable disk-shaped element that has a flat surface, generally perpendicular to the valve axis of symmetry when closed, and translates toward or away from an orifice surrounded by a narrow lip or orifice ridge. Enhanced leak tightness in the valve shut-off condition is achieved by selectively incorporating into the control plate materials that are softer than the material comprising the orifice ridge.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §119(e) to U.S.Provisional Application Ser. No. 62/190,478 titled “CONTROL PLATE IN AVALVE,” filed Jul. 9, 2015, and Provisional Application Ser. No.62/292,526 titled “CONTROL PLATE IN A VALVE,” filed Feb. 8, 2016, eachof which is incorporated by reference herein in its entirety for allpurposes.

BACKGROUND

The present invention is related to a moveable portion of a fluidcontrol valve that may be actively positioned, anywhere between anextreme open condition and an extreme closed condition, to adjust a flowof fluid passing therethrough. The invention is particularly useful invalves intended for proportional or modulating control of fluid deliverywithin industrial processes making semiconductor devices,pharmaceuticals, or fine chemicals, and many similar high-purity fluiddelivery systems that simultaneously demand a leak-tight shut-off in thefully closed condition along with proportional control. Manycombinations of metallic and elastomeric elements enhancing valveshut-off are known in the art.

SUMMARY

Applicant has invented uniquely manufacturable configurations of amoveable valve element suited for use with various sized valve orifices.The moveable disk-shaped element has a flat surface generallyperpendicular to the valve axis of symmetry when closed and translatestoward or away from an orifice surrounded by a narrow lip or orificeridge. This combination of valve structures is sometimes referred to asbeing the jet & seat class of fluid pathway element combinations. Inthis disclosure the flat surfaced element (colloquially a seat) whichcloses against the narrow lip (colloquially a jet) surrounding theorifice is often referred to as a control plate. Enhanced leak tightnessin the valve shut-off condition is provided by selectively incorporatinginto the control plate materials that are softer than the materialcomprising the lip or ridge surrounding the orifice. Control platematerials being softer than the orifice ridge-lip allows elasticdeformation of the control plate surface as it presses against theorifice ridge-lip and thereby enhances the sealing effected between thecontrol plate and the orifice ridge-lip. The disclosed arrangements canuse welding or interference press-fit pieces to avoid problemsassociated with having threads within high purity fluid pathways.

One embodiment comprises a metallic seat housing having a small diametercentral insert of polymer material held in place by a metallic retainingring pressed into a gap between the outside diameter of the polymerinsert and the inside diameter of a seat housing counterbore. Anotherembodiment comprises a ring of polymer material held in place by ametallic retaining ring pressed into a gap between the inside diameterof the polymer ring and the small internal diameter of a trepannedchannel in the control plate, and a metallic retaining ring pressed intothe gap between the outside diameter of the polymer ring and the largeinternal diameter of the trepanned channel in the control plate. Anotherembodiment comprises a small diameter central insert of a corrosionresistant Nickel alloy typically retained by welding to the largercontrol plate. Another embodiment comprises a control platesubstantially made of a corrosion resistant Nickel alloy with a coverpiece optionally made from another alloy.

In one aspect of the present disclosure, a valve control plate isprovided that is configured to sealingly engage a fluid conduit openingsurrounded by a planar orifice ridge. The valve control plate comprisesa valve control plate body and a valve seat insert. The valve controlplate body is formed from a first material having a first hardness, thevalve control plate body having a first surface configured to facetoward the fluid conduit opening. The valve control plate body has arecess defined in the first surface of the valve control plate body. Thevalve seat insert is formed from a second material having a secondhardness that is less than the first hardness, the valve seat inserthaving a first surface configured to face toward the fluid conduitopening and sealingly engage the planar orifice ridge, the valve seatinsert being received in the recess.

In some embodiments, the recess is one of a counterbore or a trepannedgroove.

In some embodiments, a volume of the second material is smaller than avolume of the first material.

In some embodiments, the first material is a metal, the recess is acounterbore defined in the first surface of the valve control platebody, the second material is a polymer material, and the valve seatinsert is retained in the counterbore by a retaining ring located at anouter periphery of the valve seat insert. In accordance with anexemplary embodiment, the valve seat insert may be configured to engagea planar orifice ridge having a diameter of 4 mm or less.

In some embodiments, the second material is a polymer material, therecess is a trepanned groove defined in the first surface of the valvecontrol plate body, the valve seat insert is ring-shaped, and the firstmaterial is a metal. In some embodiments, the valve seat insert isretained in the trepanned groove by an inner retaining ring located atan inner periphery of the valve seat insert and an outer retaining ringlocated at an outer periphery of the valve seat insert. In otherembodiments, the valve seat insert is retained in the trepanned grooveby posts, columns, and/or bridges. In accordance with an exemplaryembodiment, the valve seat insert may be configured to engage a planarorifice ridge having a diameter of 4 mm or greater.

In some embodiments, the first material is a first metal, the recess isa counterbore defined in the first surface of the control plate body,the second material is a second metal different from the first metal,and the valve seat insert is retained in the counterbore by welding thevalve seat insert to the control plate body. In accordance with anexemplary embodiment, the valve seat insert may be configured to engagea planar orifice ridge having a diameter of 4 mm or less.

In some embodiments, a region of the first surface of the valve seatinsert that sealingly engages the planar orifice ridge is planar.

In another aspect of the present disclosure, a valve bonnet for use witha control valve body is provided. The control valve body is formed froma first material having a first hardness and has a fluid conduit openingsurrounded by a planar orifice ridge. The valve bonnet comprises abonnet body, a valve diaphragm in sealing engagement with the bonnetbody at an outer periphery of the valve diaphragm, a control shaftsecured to the diaphragm, the control shaft having a shank projectingfrom the control shaft, and a valve control plate. The valve controlplate is secured to the shank and at least a portion of the valvecontrol plate is formed from a second material having a second hardnessthat is less than the first hardness, the at least a portion of thevalve control plate being configured to sealingly engage the planarorifice ridge. In some embodiments, the at least a portion of the valvecontrol plate is configured to engage a planar orifice ridge that is oneof circular and non-circular. In some embodiments, the valve diaphragmis formed integrally with the bonnet body and the control shaft isintegrally formed with the diaphragm. In other embodiments, thediaphragm is formed separately from the bonnet body and is welded to thebonnet body.

In some embodiments, the valve control plate further includes a valvecontrol plate body having a trepanned groove defined in the valvecontrol plate body, and the at least a portion of the valve controlplate is a valve seat insert that fills the trepanned groove. In someembodiments, the valve seat insert is molded into the trepanned groove,and in some embodiments, the valve seat insert is retained in thetrepanned groove by posts, columns, and/or bridges.

In another aspect of the present disclosure, a control valve isprovided. The control valve comprises a valve body, a bonnet bodysecured to the valve body, a valve diaphragm, a control shaft, and avalve control plate. The valve body has a fluid inlet conduitterminating at a first fluid conduit opening, a fluid outlet conduitcommencing at a second fluid conduit opening, and an orifice ridgeformed from a first material having a first hardness and surrounding thefirst fluid conduit opening. The valve diaphragm is in sealingengagement with the bonnet body at an outer periphery of the valvediaphragm. The control shaft is secured to the diaphragm, and a shankprojects from the control shaft. The valve control plate is secured tothe shank and at least a portion of the valve control plate is formedfrom a second material having a second hardness that is less than thefirst hardness, the at least a portion of the valve control plate beingconfigured to sealingly engage the orifice ridge.

In some embodiments, the orifice ridge is circular or non-circular.

In some embodiments, the valve control plate includes a valve controlplate body having a trepanned groove defined in the valve control platebody, and the at least a portion of the valve control plate is a valveseat insert that fills the trepanned groove. In some embodiments, thevalve seat insert is molded into the trepanned groove, and in someembodiments, the valve seat insert is retained in the trepanned grooveby posts, columns, and/or bridges.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectioned perspective view of a representative valvewith a control plate having a polymer material insert and a smallorifice ridge of maximal span.

FIG. 2 is a cross-sectioned perspective view of a representative valvewith a control plate having a polymer material insert and a largeorifice ridge of typical span.

FIG. 3 is a cross-sectioned perspective view of a representative valvewith a control plate having a soft corrosion resistant alloy insert anda small orifice ridge of maximal span.

FIG. 4 is a cross-sectioned perspective view of a representative valvewith a control plate having a soft corrosion resistant alloy body and alarge orifice ridge of typical span.

FIG. 5 is a cross-sectioned perspective view of another representativevalve with an alternate design soft corrosion resistant alloy controlplate.

FIG. 6A is a cross-sectioned perspective view of another representativevalve with an alternate design polymer insert control plate.

FIG. 6B is an enlarged perspective section view of the control plateillustrated in FIG. 6A to further illustrate construction of the polymermaterial insert.

FIG. 6C is a view of a molded polymer insert without the metal controlplate body, to further illustrate the geometry of the polymer materialinsert.

FIG. 6D is an enlarged perspective section view of an alternate controlplate for use in the valve illustrated in FIG. 6A to further illustrateconstruction of the polymer material insert.

FIG. 6E is a view of a molded polymer insert without the metal controlplate body, to further illustrate the geometry of the polymer materialinsert

FIG. 6F is an enlarged perspective section view of another alternatecontrol plate for use in the valve illustrated in FIG. 6A to furtherillustrate construction of the polymer material insert.

FIG. 6G is a view of a molded polymer insert without the metal controlplate body, to further illustrate the geometry of the polymer materialinsert.

DETAILED DESCRIPTION

Embodiments of the present invention are not limited in theirapplication to the details of construction and the arrangement ofcomponents set forth in the following description or illustrated in thedrawings. Aspects of the present invention are capable of otherembodiments and of being practiced or of being carried out in variousways. Also, the phrasing and terminology used herein is for the purposeof description and should not be regarded as limiting. The use of“including,” “comprising,” or “having,” “containing,” “involving,” andvariations thereof herein, is meant to encompass the items listedthereafter and equivalents thereof as well as additional items. The useof directional adjectives “inner”, “outer,” “upper,” “lower,” and liketerms, are meant to assist with understanding relative relationshipsamong design elements and should not be construed as meaning an absolutedirection in space nor regarded as limiting. In the following designdiscussions fluid flow is typically described as proceeding from a firstfluid conduit, through the controlling portion of the valve, and thenthrough a second fluid conduit. Designers will of course appreciate thediscussed direction is merely a matter of descriptive convenience, fluidflow may proceed in an opposite sequence, and should not be consideredas limiting.

In most current high purity valve designs a diaphragm type of moveablesealing structure is the preferred approach. Using a diaphragm tocontain a controlled fluid, while allowing easy motion of a moveablecontrol element, has become standard practice. In many such valvedesigns the diaphragm serves as the moveable control element and valveshut-off is achieved by having the diaphragm itself press against anarrow ring of polymer material surrounding a fluid conduit opening.Designers making valves intended for proportional, or modulating,control of fluid delivery within industrial processes makingsemiconductor devices may find direct contacting type diaphragm valveshave insufficiently gradual control curves. One type of knownalternative design has a substantially flat control plate moving towardor away from a metallic lip or orifice ridge surrounding a fluid conduitopening. Complications may however arise when the diaphragm itself isnot the element best suited to blocking fluid flow through the valve andshut-off sealing against a metallic structure can be problematic.

FIG. 1 illustrates a representative example of a proportional controlvalve 100 using diaphragm sealing and also having a control plate 140which abuts an orifice ridge 118 surrounding a centrally located fluidconduit opening 112. The proportional control valve 100 comprises avalve body 119 having a first fluid conduit 110 and a second fluidconduit 114, each of which communicates fluid to or from a valve chamber150, and a valve bonnet (bonnet body) 169 sealed to the valve body 119by a gasket 165, the bonnet 169 having a diaphragm 167 allowing movementof the attached control plate 140 within the valve chamber 150. Themanner of controlling fluid flow may be further understood byconsidering the fluid conduit opening 112, in fluid communication withthe first fluid conduit 110 and surrounded by the orifice ridge 118,whereby at least a portion of the control plate 140 may be moved towardor away from the orifice ridge 118 to create a small clearance controlgap (not shown) through which fluid may controllably flow. Thecontrollable fluid flow may transit into the valve chamber 150 fromwhence it may exit through an offset fluid conduit opening 116 in fluidcommunication with the second fluid conduit 114. In the present examplevalve 100, an actuator (not shown) may apply a retracting force to acontrol shaft 182 to deflect the diaphragm 167 and thereby modulate theconductance through the valve by changing the control gap. In thepresent FIG. 1 illustration the valve 100 is completely closed in ano-flow condition so there is no control gap shown.

Achieving leak-free valve shut-off when the control plate 140 contactsthe orifice ridge 118 may be difficult and moreover the criteria forwhat constitutes leak-free operation may differ among designapplications. For example, not producing any gas bubbles when the valveoutlet is submerged in water might be sufficient in one circumstancewhile having a helium gas leak rate less than 10 e-9 sccm/sec might berequired for another situation. A valve design having a polymer materialcontact a metallic material upon closure is known to generally provideamong the most leak-tight of shut-off arrangements. But polymermaterials usually absorb moisture and consequently in high purityapplications it is desirable to minimize the total amount of polymermaterial exposed to the controlled fluid. In the representativeproportional control valve 100 this goal of reducing polymer content isachieved by creating a control plate 140 comprising a metallic controlplate body 146 and an insert 130 of polymer material having a relativelysmall volume. The orifice ridge 118 may be considered as having a“maximal span” relative to the polymer insert 130 in that the orificeridge engages the polymer insert adjacent an outer periphery of theinsert.

A metallic control plate body 146 of the control plate 140 can bemachined as a flat disk having a central thru-hole 142 with acounterbore 144 on the side intended to face the central fluid conduitopening 112. The counterbore 144 will enable the metallic control platebody 146 to function as a seat housing whereby a polymer seat insert 130may be retained therein to provide a more compliant sealing material ofreduced volume. In manufacturing the illustrated valve design 100 thecontrol plate body 146 is placed onto a shank 181, projecting from thecontrol shaft 182 and diaphragm 167, which passes through the centralthru-hole 142. The shank 181 and control plate body 146 may be weldedtogether at the central thru-hole 142 interface using electron beam,laser, TIG, or any equivalent welding process. Any resulting minor weldbead excess may be machined off to match the bottom of the counterbore144. The polymer material insert 130 may subsequently be placed into thecounterbore 144 and held in place by inserting a metallic retaining ring132 into a space around the outer periphery of the polymer materialinsert 130 within the outer diameter of the counterbore 144. Thecomplete assembly may then undergo final finishing for flatness (bylapping, for example) as needed for good valve function. This designapproach is especially advantageous for valves having an orifice ridgeof about 4 mm diameter or less.

The polymer material insert 130 includes a planar first surfaceconfigured to sealingly engage the planar upper end of the orifice ridge118.

FIG. 2 illustrates a representative example of a proportional controlvalve 200 using diaphragm sealing and also having a control plate 240which abuts an orifice ridge 218 surrounding a central fluid conduitopening 212. The proportional control valve 200 comprises a valve body219 having a first fluid conduit 210 and a second fluid conduit 214,each of which communicates fluid to or from a valve chamber 250, and avalve bonnet 269 sealed to the valve body 219 by a gasket 265, thebonnet 269 having a diaphragm 267 allowing movement of the attachedcontrol plate 240 within the valve chamber 250. The manner ofcontrolling fluid flow may be further understood by considering thefluid conduit opening 212, in fluid communication with the first fluidconduit 210 and surrounded by the orifice ridge 218, whereby at least aportion of the control plate 240 may be moved toward or away from theorifice ridge 218 to create a small clearance control gap (not shown)through which fluid may controllably flow. The controllable fluid flowmay transit into the valve chamber 250 from whence it may exit throughan offset fluid conduit opening 216 in fluid communication with thesecond fluid conduit 214. In the present example valve 200, an actuator(not shown) may apply a retracting force to a control shaft 282 todeflect the diaphragm 267 and thereby modulate the conductance throughthe valve by changing the control gap. In the present FIG. 2illustration the valve 200 is completely closed in a no-flow conditionso there is no control gap shown.

In the representative proportional control valve 200 the goal ofreducing polymer content is achieved by creating a control plate 240comprising a metallic control plate body 246 and a ring-shaped insert230 of polymer material having a relatively small volume. The orificeridge 218 may be considered as having a “typical span” relative to thering-shaped insert 230 in that the orifice ridge engages the insertadjacent a more central region of the insert 230 located between aninner periphery and an outer periphery of the insert. It should beappreciated that FIG. 2 is not drawn to scale, and that the volume ofthe polymer can be less than that illustrated in at least someembodiments. The metallic control plate body 246 of the control plate240 can be machined as a flat disk having a central thru-hole 242 and atrepanned (i.e., ring-shaped) groove 245 on the side intended to facethe central fluid conduit opening 212. The trepanned groove 245 willenable the metallic control plate body 246 to function as a seat housingwhereby a polymer material insert 230 may be retained therein to providea more compliant sealing material of reduced volume. In manufacturingthe illustrated valve design 200 the ring-shaped polymer material insert230 may be placed into the trepanned groove 245 and held in place byinserting a metallic inner retaining ring 234 into a space around theinner diameter of the trepanned groove 245 within the inner diameter ofthe ring-shaped polymer insert 230, and inserting a metallic outerretaining ring 236 into a space around the outer periphery of thering-shaped polymer insert 230 within the outer diameter of thetrepanned groove 245. The control plate 240 is subsequently placed ontoa shank 281, projecting from the control shaft 282 and diaphragm 267,which passes through the central thru-hole 242. The shank 281 andcontrol plate body 246 may be welded together at the central thru-hole242 interface using electron beam, laser, TIG, or any equivalent weldingprocess. Any resulting minor weld bead excess may be machined off thecontrol plate 240 surface as well as any splatter on the ring-shapedpolymer insert 230. The complete assembly may then undergo finalfinishing for flatness (by lapping, for example) as needed for goodvalve function. This design approach is especially advantageous forvalves having an orifice ridge maximal span greater than about 4 mm. Itshould be appreciated the orifice ridge maximal span may be other than adiameter in the case of a non-circular orifice ridge structure.

In addition to concerns discussed above regarding moisture absorption bypolymer materials, it is also known that many gases will diffuse throughpolymers. Although the diffusion occurs at a very low rate it may amountto detectable quantities which are considered undesirable or evenproblematic. Additionally, in nuclear science applications a problematicdiffusion of radioactive gas may also lead to a simultaneous destructionof the polymer material. A valve having metal to metal sealing is freeof these concerns but it is difficult to achieve good shut-offperformance in such designs. Moreover, cold welding between very cleanvalve metallic components can be a potential problem. One designapproach is to make the valve of two dissimilar metallic materials toavoid cold welding and also provide dissimilar hardness to enhanceshut-off. FIG. 3, FIG. 4, and FIG. 5 illustrate embodiments of a controlplate for implementing a metal to metal valve design.

The polymer material insert 230 includes a planar first surfaceconfigured to sealingly engage the planar upper end of the orifice ridge218.

FIG. 3 illustrates a representative example of a proportional controlvalve 300 using diaphragm sealing and also having a control plate 340which abuts an orifice ridge 318 surrounding a central fluid conduitopening 312. The proportional control valve 300 comprises a valve body319 having a first fluid conduit 310 and a second fluid conduit 314,each of which communicates fluid to or from a valve chamber 350, and avalve bonnet 369 sealed to the valve body 319 by a gasket 365, thebonnet 369 having a diaphragm 367 allowing movement of the attachedcontrol plate 340 within the valve chamber 350. The manner ofcontrolling fluid flow may be further understood by considering thefluid conduit opening 312, in fluid communication with the first fluidconduit 310 and surrounded by the orifice ridge 318, whereby at least aportion of the control plate 340 may be moved toward or away from theorifice ridge 318 to create a small clearance control gap (not shown)through which fluid may controllably flow. The controllable fluid flowmay transit into the valve chamber 350 from whence it may exit throughan offset fluid conduit opening 316 in fluid communication with thesecond fluid conduit 314. In the present example valve 300, an actuator(not shown) may apply a retracting force to a control shaft 382 todeflect the diaphragm 367 and thereby modulate the conductance throughthe valve by changing the control gap. In the present FIG. 3illustration the valve 300 is completely closed in a no-flow conditionso there is no control gap shown.

In the representative proportional control valve 300 enhancing shut-offperformance is achieved by creating a control plate 340 comprising ametallic control plate body 346 and a metallic insert 330 of lesshardness than the orifice ridge 318. The orifice ridge 318 may beconsidered as having a “maximal span” relative to the metallic insert330 in that the orifice ridge engages the metallic insert adjacent anouter periphery of the insert. The metallic control plate body 346 ofthe control plate 340 can be machined as a flat disk having a centralthru-hole 342 with a counterbore 344 on the side intended to face thecentral fluid conduit opening 312. The counterbore 344 will enable themetallic control plate body 346 to function as a seat housing whereby anannealed, or preferably fully annealed, corrosion resistant metallicalloy insert 330 may be retained therein to provide a more compliantsealing material. In manufacturing the illustrated valve design 300 thecontrol plate body 346 is placed onto a shank 381, projecting from thecontrol shaft 382 and diaphragm 367, which passes through the centralthru-hole 342.

The shank 381 and control plate body 346 may be welded together at thecentral thru-hole 342 interface using electron beam, laser, TIG, or anyequivalent welding process. Any resulting minor weld bead excess may bemachined off to match the bottom of the counterbore 344. The annealed,or fully annealed, corrosion resistant metallic alloy insert 330 maysubsequently be placed into the counterbore 344 and held in place byusing electron beam, laser, TIG, or any equivalent welding processaround the outer periphery of the insert 330 and the inner diameter ofthe counterbore 344. Alternatively, an interference fit between theouter diameter of the metallic alloy insert 330 and the inner diameterof the counterbore 344 may be considered sufficient to retain the insert330. The complete assembly may then undergo final finishing for flatness(by lapping, or single point diamond turning, for example) as needed forgood valve function. This design approach is especially advantageous forvalves having an orifice ridge of about 4 mm diameter or less. In atypical application the orifice ridge 318 will be made of one alloywhile the metallic alloy seat insert 330 will be made from a differentalloy. One usual choice of materials is type 316 stainless for theorifice ridge 318 and a corrosion resistant nickel alloy (such asHastelloy® C-22® available from Haynes International) for the insert330.

The metallic insert 330 includes a planar first surface configured tosealingly engage the planar upper end of the orifice ridge 318.

FIG. 4 illustrates a representative example of a proportional controlvalve 400 using diaphragm sealing and also having a control plate 440which abuts an orifice ridge 418 surrounding a central fluid conduitopening 412. The proportional control valve 400 comprises a valve body419 having a first fluid conduit 410 and a second fluid conduit 414,each of which communicates fluid to or from a valve chamber 450, and avalve bonnet 469 sealed to the valve body 419 by a gasket 465, thebonnet 469 having a diaphragm 467 allowing movement of the attachedcontrol plate 440 within the valve chamber 450. The manner ofcontrolling fluid flow may be further understood by considering thefluid conduit opening 412, in fluid communication with the first fluidconduit 410 and surrounded by an orifice ridge 418, whereby at least aportion of the control plate 440 may be moved toward or away from theorifice ridge 418 to create a small clearance control gap (not shown)through which fluid may controllably flow. The controllable fluid flowmay transit into the valve chamber 450 from whence it may exit throughan offset fluid conduit opening 416 in fluid communication with thesecond fluid conduit 414. In the present example valve 400, an actuator(not shown) may apply a retracting force to a control shaft 482 todeflect the diaphragm 467 and thereby modulate the conductance throughthe valve by changing the control gap. In the present FIG. 4illustration the valve 400 is completely closed in a no-flow conditionso there is no control gap shown.

In the representative proportional control valve 400 enhancing shut-offperformance is achieved by creating a control plate 440 comprising ametallic control plate body 446 of less hardness than the orifice ridge418 and a metallic cover piece 430. The orifice ridge 418 may beconsidered as having a “typical span” relative to the control plate body446 in that the orifice ridge engages the control plate body adjacent amore central region of the control plate body 446 located between aninner periphery and an outer periphery of the control plate body 446.The metallic control plate body 446 of the control plate 440 can bemachined from an annealed, or preferably fully annealed, corrosionresistant alloy as a flat disk having a central thru-hole 442 with acounterbore 444 on the side intended to face the central fluid conduitopening 412. The counterbore 444 enables the attachment process byproviding access to the moveable valve elements. In manufacturing theillustrated valve design 400 the control plate body 446 is placed onto ashank 481, projecting from the control shaft 482 and diaphragm 467,which passes through the central thru-hole 442. The shank 481 andcontrol plate body 446 may be welded together at the central thru-hole442 interface using electron beam, laser, TIG, or any equivalent weldingprocess. Any resulting minor weld bead excess may be machined off tomatch the bottom of the counterbore 444. A suitable metallic cover piece430 may subsequently be placed into the counterbore 444 and held inplace by using electron beam, laser, TIG, or any equivalent weldingprocess around the outer periphery of the cover piece 430 and the innerdiameter of the counterbore 444. Alternatively, an interference fitbetween the outer diameter of the metallic cover piece 430 and the innerdiameter of the counterbore 444 may be considered sufficient to retainthe cover piece 430. The complete assembly may then undergo finalfinishing for flatness (by lapping, or single point diamond turning, forexample) as needed for good valve function. This design approach isespecially advantageous for valves having an orifice ridge maximal spangreater than about 4 mm. It should be appreciated the orifice ridgemaximal span may be other than a diameter in the case of a non-circularorifice ridge structure. In a typical application the orifice ridge 418will be made of one alloy while the metallic control plate body 446 willbe made from a different alloy. One usual choice of materials is type316 stainless for the orifice ridge 418 and a corrosion resistant nickelalloy (such as Hastelloy® C-22® available from Haynes International) forthe control plate body 446. The metallic cover piece 430 may be madefrom the same material as either the orifice ridge 418 or the controlplate 440, or from yet another different alloy.

The cover piece 430 and the control plate body 446 are provided asseparate components in FIG. 4 to allow for improved welding of thecontrol plate 440 to the shank 481. First, the control plate body 446 iswelded to the shank 481. Next the cover piece 430 is welded to thecontrol plate body 446. Then cover piece 430 and the control plate body446 can undergo finishing for flatness (e.g. by lapping, or single pointdiamond turning, or another method).

In some embodiments, the structure of FIG. 4 could be provided withoutthe cover piece 430, because the cover piece 430 is not used to engagethe orifice ridge 418.

The term cover piece, as used herein, is used to describe an insert inwhich the insert itself is not used to sealingly engage the orificeridge.

The control plate body 446 includes a planar first surface configured tosealingly engage the planar upper end of the orifice ridge 418.

FIG. 5 illustrates a representative example of a proportional controlvalve 500 using diaphragm sealing and also having a control plate 540which abuts an orifice ridge 518 surrounding a central fluid conduitopening 512. The proportional control valve 500 comprises a valve body519 having a first fluid conduit 510 and a second fluid conduit 514,each of which communicates fluid to or from a valve chamber 550, and avalve bonnet 569 sealed to the valve body 519 by a gasket 565, thebonnet 569 having a diaphragm 567 allowing movement of the attachedcontrol plate 540 within the valve chamber 550. The manner ofcontrolling fluid flow may be further understood by considering thefluid conduit opening 512, in fluid communication with the first fluidconduit 510 and surrounded by an orifice ridge 518, whereby at least aportion of the control plate 540 may be moved toward or away from theorifice ridge 518 to create a small clearance control gap (not shown)through which fluid may controllably flow. The controllable fluid flowmay transit into the valve chamber 550 from whence it may exit throughan offset fluid conduit opening 516 in fluid communication with thesecond fluid conduit 514. In the present example valve 500 an actuator(not shown) may apply a retracting force to a control shaft 582 todeflect the diaphragm 567 and thereby modulate the conductance throughthe valve by changing the control gap. In the present FIG. 5illustration the valve 500 is completely closed in a no-flow conditionso there is no control gap shown.

The metallic control plate 540 can be machined from an annealed orpreferably fully annealed corrosion resistant alloy, of less hardnessthan the orifice ridge, as a flat disk having a blind centralcounterbore 542 on the side intended to face the diaphragm 567. Inmanufacturing the illustrated valve design 500 the control plate 540 maybe press fit onto a shank 581, projecting from the control shaft 582 anddiaphragm 567. Alternatively, the shank 581 and control plate 540 may bewelded together using electron beam, laser, or any equivalentlyenergetic welding process suitable to penetrate the thin central portion530 of the control plate 540 and fuse it to the shank 581. It should benoted that in the embodiment depicted in FIG. 5, the shank 581 mayextend deeper into the control plate 540 than, for example, theembodiments depicted in FIGS. 3 and 4 to aid in the welding process. Thethin central portion 530 may further include a detent or other type ofweld preparation (not shown) to reduce the amount of material in thecentral portion 530 of the control plate to minimize the amount ofenergy or time needed to weld the central portion 530 of the controlplate 540 to the shank 581. Any resulting minor weld bead excess may bemachined off and the complete assembly may then undergo final finishingfor flatness (by lapping, or single point diamond turning, for example,or another method) as needed for good valve function. This designapproach is especially advantageous due to the lesser number of machinedpieces and its suitability for use with a variety of orifice ridge sizesand shapes. It should be appreciated the orifice ridge maximal span maybe other than a diameter in the case of a non-circular orifice ridgestructure and an ensemble plurality of coplanar orifice ridges is alsocontemplated. In a typical application the orifice ridge 518 will bemade of one alloy while the metallic control plate 540 will be made froma different alloy. One usual choice of materials is type 316 stainlessfor the orifice ridge 518 and a corrosion resistant nickel alloy (suchas Hastelloy® C-22® available from Haynes International) for the controlplate 540.

The control plate 540 includes a planar first surface configured tosealingly engage the planar upper end of the orifice ridge 518

FIG. 6A and FIG. 6B illustrate a representative example of aproportional control valve 600 using diaphragm sealing and also having acontrol plate 640 which abuts an orifice ridge 618 surrounding an innerfluid conduit opening 612. The proportional control valve 600 comprisesa valve body 619 having a first fluid conduit 610 and a second fluidconduit 614, each of which communicates fluid to or from a valve chamber650, and a valve bonnet 669 sealed to the valve body 619 by a gasket665, the bonnet 669 having a diaphragm 667 allowing movement of theattached control plate 640 within the valve chamber 650. The manner ofcontrolling fluid flow may be further understood by considering theinner fluid conduit opening 612, in fluid communication with the firstfluid conduit 610 and surrounded by the orifice ridge 618, whereby atleast a portion of the control plate 640 may be moved toward or awayfrom the orifice ridge 618 to create a small clearance control gap (notshown) through which fluid may controllably flow. The controllable fluidflow may transit into the valve chamber 650 from whence it may exitthrough an outer fluid conduit opening 616 in fluid communication withthe second fluid conduit 614. In the present example valve 600, anactuator (not shown) may apply a retracting force to a control shaft 682to deflect the diaphragm 667 and thereby modulate the conductancethrough the valve by changing the control gap. In the present FIG. 6Aillustration the valve 600 is completely closed in a no-flow conditionso there is no control gap shown.

In the representative proportional control valve 600 the goal ofreducing polymer content is achieved by creating a control plate 640comprising a metallic control plate body 646 and a molded insert 630 ofpolymer material. As may be seen in FIG. 6B, the metallic control platebody 646 of the control plate 640 can be machined as a flat disk havinga central thru-hole 642 and a plurality of concentric ring-shapedgrooves 648 on the side intended to face the inner fluid conduit opening612. The grooves 648 enable the metallic control plate body 646 tofunction as a seat housing whereby a polymer material insert 630 may beretained therein, as will be further explained, to provide a morecompliant sealing material of reduced volume. The remaining metal 649between the concentric grooves 648 in the control plate body 646provides meaningful reduction of the total volume of the molded insert630. Vent holes 644, defined in the flat back side of the disk facingaway from the inner fluid opening 612, are made centered between thegrooves 648 deep enough with sufficient diameter to intersect thebottoms of adjacent grooves 648 while leaving the majority of theremaining metal 649 intact. In manufacturing the illustrated controlplate 640 the polymer material insert 630 may be formed by compressionmolding (e.g. starting with polychlorotrifluoroethene (PCTFE) powder andpolymerizing under the effect of heat and pressure) directly into thecontrol plate body 646 by known methods. During the molding processbridges 634 of polymer material will surround parts of the remainingmetal 649 and fill the vent holes 644. The polymer material bridges 634surrounding the remaining metal 649 thus lock the molded polymer insert630 into the metallic control plate body 646. FIG. 6C shows aperspective view of a molded polymer insert 630, with the metalliccontrol plate body 646 not shown for the purpose of illustrating thegeometry of the molded polymer insert 630. The molded polymer insert 630has a plurality of annular ridges 638, that are complementary with thegrooves 648 and which fill the grooves 648 that are defined in thecontrol plate body 646.

The control plate 640 comprising the metallic control plate body 646including the molded polymer insert 630 may be attached to a shank 681,projecting from the control shaft 682 and diaphragm 667, by press fitinto the central thru-hole 642. Alternatively, prior to the abovedescribed molding, the control plate body 646 may first be placed ontothe shank 681 and welded together at the central thru-hole 642 interfaceusing electron beam, laser, TIG, or any equivalent welding process. Anyresulting minor weld bead excess may be machined off the control platebody 646 surface before molding the insert 630 into the control platebody 646. The process sequence choice will depend upon practitioners'preference in compression molding techniques. The complete assembly maythen undergo final finishing for flatness (by lapping, for example) asneeded for good valve function. This design approach is especiallyadvantageous for use with valve bodies having a variety of orifice ridgesizes and shapes. It should be appreciated the orifice ridge maximalspan may be other than a diameter in the case of a non-circular orificeridge structure. Careful examination of the illustrated example of FIG.6A will reveal the orifice ridge 618 is circular but placed offgeometric center of the diaphragm 667 and control plate 640 toaccommodate a correspondingly large non-circular outer fluid opening 617because the orifice ridge is so large in diameter.

An alternate control plate 660 suitable for use in the representativeproportional control valve 600 is illustrated in FIG. 6D. A metalliccontrol plate body 676 of the control plate 660 can be machined as aflat disk having a central thru-hole 672 and a wide shallow ring-shapedgroove 675 on the side intended to face the inner fluid conduit opening612. The groove 675 enables the metallic control plate body 676 tofunction as a seat housing whereby a polymer material insert 670 may beretained therein, as will be further explained, to provide a morecompliant sealing material of reduced volume. A plurality of thru-holes674 defined in the flat back side of the disk facing away from the innerfluid opening 612 penetrate the wide shallow ring-shaped groove 675. Inmanufacturing the illustrated control plate 660 the polymer materialinsert 670 may be formed by compression molding (e.g. starting withPCTFE powder and polymerizing under the effect of heat and pressure)directly into the control plate body 676 by known methods. During themolding process a plurality of columns 673 of polymer material will fillthe thru-holes 674 thereby frictionally locking the polymer materialinto the groove 675 defined in the metallic control plate body 676. Thegeometry of the polymer material insert 670 that is formed by themolding process is shown in FIG. 6E, with the control plate body 676 notshown for illustration purposes. The control plate 660 comprising themetallic control plate body 676 including the molded polymer insert 670may be attached to a shank 681, projecting from the control shaft 682and diaphragm 667, by press fit into the central thru-hole 672, orattached in another manner as previously described.

Another alternate control plate 680 suitable for use in therepresentative proportional control valve 600 is illustrated in FIG. 6F.A metallic control plate body 696 of the control plate 680 can bemachined as a flat disk having a central thru-hole 692, a wide shallowcounterbore 695, and a plurality of wedge-shaped (being approximatelycircular sectors) cavities 697,698 cut into the bottom of thecounterbore 695 on the side intended to face the inner fluid conduitopening 612. The counterbore 695 and plurality of cavities 697,698enable the metallic control plate body 696 to function as a seat housingwhereby a polymer material insert 690 may be retained therein, as willbe further explained, to provide a more compliant sealing material ofreduced volume. The metal between the between the plurality ofwedge-shaped cavities 697,698, in the wide shallow counterbore 695 ofthe control plate body 696, form radial ribs 699. Vent holes 691,defined in the flat back side of the disk facing away from the innerfluid opening 612, are made centered over the radial ribs 699 deepenough with sufficient diameter to intersect the bottoms of adjacentwedge-shaped cavities 697,698 while leaving the majority of theremaining metal rib 699 intact. A plurality of thru-holes 694, alsodefined in the flat back side of the disk facing away from the innerfluid opening 612, penetrate the bottom of each of the wedge-shapedcavities 697,698. In manufacturing the illustrated valve design 600 thepolymer material insert 690 may be formed by compression molding (e.g.starting with PCTFE powder and polymerizing under the effect of heat andpressure) directly into the control plate body 696 by known methods.During the molding process polymer material will fill the thru-holes 694and surround the metal radial ribs 699 to fill the vent holes 691. Themolded polymer material forms bridges 689 to fill the vent holes andposts 693 to fill the thru-holes 694. The molded polymer material alsoforms wedge portions of the insert 690 to fill respective wedge-shapedcavities 697, 698. The polymer material surrounding the metal ribs 699thus lock the molded insert 690 into the metallic control plate body696. The geometry of the polymer material insert 690 that is formed bythe molding process is shown in FIG. 6G, with the control plate body 696not shown for illustration purposes. The control plate 680 comprisingthe metallic control plate body 696 including the molded polymer insert690 may be attached to a shank 681, projecting from the control shaft682 and diaphragm 670, by press fit into the central thru-hole 692, orattached in another manner as previously described.

In each of FIGS. 6A-6G, the respective polymer material insert 630, 670,690 includes a planar first surface configured to sealingly engage theplanar upper end of the orifice ridge 618.

It should be appreciated that the specific sizes of features shown inFIGS. 6A-6G may be varied and are not necessarily drawn to scale.

Referring again to FIG. 2, the ring-shaped insert 230 could be molded inthe control plate body 246 of the control plate 240 and secured withinthe control plate body 246 of the control plate 240 by retainingfeatures such as the structure of FIGS. 6A-6G. That is, for example, thering-shaped insert 230 could have columns that are positioned inthru-holes defined in the control plate body 246, posts that arepositioned in thru-holes defined in the control plate body 246, and/orbridges that are positioned in vent holes defined in the control platebody in a manner similar to that described with respect to FIGS. 6A-6G.

The counterbores and grooves described above are examples of recessesthat can be defined in a control plate body. In some embodiments, aninsert can be secured in another type of recess that is defined in thecontrol plate body.

In some embodiments, a retention mechanism is used to retain an insertin one or more counterbores and/or one or more grooves defined in acontrol plate body. Some examples of a retention mechanism include aretaining ring located at an outer periphery of the insert, an innerretaining ring located at an inner periphery of the insert and an outerretaining ring located at an outer periphery of the insert, a post, acolumn, a bridge, and a weld. Other retention mechanisms are possible.It should be appreciated that although embodiments of the presentdisclosure have been primarily described with respect to diaphragmsealed valves in which a control plate is disposed below and attached toor integrally formed with the diaphragm, aspects of the presentdisclosure may be readily adapted for use with other types of valves,such as bellows sealed valves similar to those described in U.S. Pat.No. 3,295,191. Moreover, although embodiments of the present disclosurehave been described with respect to control valves in which an actuatoris used to move an orifice ridge sealing surface of the control platetoward and away from an orifice ridge, this movement need not need notbe uniform across the orifice ridge sealing surface of the controlplate. For example, embodiments of the present disclosure may readily beused with a valve stroke amplification mechanism, such as disclosed inUS Patent Publication No. US2016/0138730 A1, in which an amplifier discmay be used to effect a wedge shaped gap having a higher conductancethan would otherwise be obtained.

Although the embodiments depicted in FIGS. 1-6A are all depicted asshowing a valve bonnet body 169, 269, 369, 469, 569, 669 in which thediaphragm 167, 267, 367, 467, 567, 667 is integrally formed with thebonnet body, it should be appreciated that the present invention is notso limited. Indeed, embodiments of the present disclosure encompassdiaphragms that are stamped, punched, or cut out of a piece of sheetmetal that is later attached (for example, by welding) to a bonnet body,as well as those in which the diaphragm and bonnet body are integrallyformed from a single block of starting material, as shown herein.

Having thus described several aspects of at least one embodiment of thisinvention, it is to be appreciated various alterations, modifications,and improvements will readily occur to those skilled in the art. Suchalterations, modifications, and improvements are intended to be part ofthis disclosure, and are intended to be within the scope of theinvention. Accordingly, the foregoing description and drawings are byway of example only.

What is claimed is:
 1. A valve control plate configured to sealinglyengage a fluid conduit opening surrounded by a planar orifice ridge, thevalve control plate comprising: a valve control plate body formed from afirst material having a first hardness, the valve control plate bodyhaving a first surface configured to face toward the fluid conduitopening, the valve control plate body having a recess defined in thefirst surface of the valve control plate body; and a valve seat insertformed from a second material having a second hardness that is less thanthe first hardness, the valve seat insert having a first surfaceconfigured to face toward the fluid conduit opening and sealingly engagethe planar orifice ridge, and the valve seat insert being received inthe recess.
 2. The valve control plate of claim 1, wherein the recess isone of a counterbore and a trepanned groove.
 3. The valve control plateof claim 1, wherein a volume of the second material is smaller than avolume of the first material.
 4. The valve control plate of claim 3,wherein the first material is a metal, the recess is a counterboredefined in the first surface of the valve control plate body, the secondmaterial is a polymer material, and the valve seat insert is retained inthe counterbore by a retaining ring located at an outer periphery of thevalve seat insert.
 5. The valve control plate of claim 4, wherein thevalve seat insert is configured to engage a planar orifice ridge havinga diameter of 4 mm or less.
 6. The valve control plate of claim 1,wherein the second material is a polymer material, the recess is atrepanned groove defined in the first surface of the valve control platebody, the valve seat insert is ring-shaped, and the first material is ametal.
 7. The valve control plate of claim 6, wherein the valve seatinsert is retained in the trepanned groove by an inner retaining ringlocated at an inner periphery of the valve seat insert and an outerretaining ring located at an outer periphery of the valve seat insert.8. The valve control plate of claim 7, wherein the valve seat insert isconfigured to engage a planar orifice ridge having a diameter of 4 mm orgreater.
 9. The valve control plate of claim 6, wherein the valve seatinsert is retained in the trepanned groove by at least one of posts,columns, and bridges.
 10. The valve control plate of claim 1, whereinthe first material is a first metal, the recess is a counterbore definedin the first surface of the control plate body, the second material is asecond metal different from the first metal, and the valve seat insertis retained in the counterbore by welding the valve seat insert to thecontrol plate body.
 11. The valve control plate of claim 10, wherein thevalve seat insert is configured to engage a planar orifice ridge havinga diameter of 4 mm or less.
 12. The valve control plate of claim 1,wherein a region of the first surface of the valve seat insert thatsealingly engages the planar orifice ridge is planar.
 13. A valve bonnetfor use with a control valve body, the control valve body being formedfrom a first material having a first hardness and having a fluid conduitopening surrounded by a planar orifice ridge, the valve bonnetcomprising: a bonnet body; a valve diaphragm in sealing engagement withthe bonnet body at an outer periphery of the valve diaphragm; a controlshaft secured to the valve diaphragm, the control shaft having a shankprojecting from the control shaft; and a valve control plate secured tothe shank, at least a portion of the valve control plate being formedfrom a second material having a second hardness that is less than thefirst hardness, the at least a portion of the valve control plate beingconfigured to sealingly engage the planar orifice ridge.
 14. The valvebonnet of claim 13, wherein the at least a portion of the valve controlplate is configured to engage a planar orifice ridge that is one ofcircular and non-circular.
 15. The valve bonnet of claim 13, wherein thevalve diaphragm is formed integrally with the bonnet body, and thecontrol shaft is integrally formed with the valve diaphragm.
 16. Thevalve bonnet of claim 13, wherein the diaphragm is formed separatelyfrom the bonnet body, and is welded to the bonnet body.
 17. The valvebonnet of claim 13, wherein the valve control plate further comprises avalve control plate body having a trepanned groove defined in the valvecontrol plate body, and the at least a portion of the valve controlplate is a valve seat insert that fills the trepanned groove.
 18. Thevalve bonnet of claim 17, wherein the valve seat insert is molded intothe trepanned groove.
 19. The valve bonnet of claim 18, wherein thevalve seat insert is retained in the trepanned groove by at least one ofposts, columns, and bridges.
 20. A control valve comprising: a valvebody having a fluid inlet conduit terminating at a first fluid conduitopening, a fluid outlet conduit commencing at a second fluid conduitopening, and an orifice ridge formed from a first material having afirst hardness and surrounding the first fluid conduit opening; a bonnetbody secured to the valve body; a valve diaphragm in sealing engagementwith the bonnet body at an outer periphery of the valve diaphragm; acontrol shaft secured to the valve diaphragm, and a shank projectingfrom the control shaft; and a valve control plate secured to the shank,at least a portion of the valve control plate being formed from a secondmaterial having a second hardness that is less than the first hardness,the at least a portion of the valve control plate being configured tosealingly engage the orifice ridge.
 21. The control valve of claim 20,wherein the orifice ridge is one of circular and non-circular.
 22. Thecontrol valve of claim 20, wherein the valve control plate includes avalve control plate body having a trepanned groove defined in the valvecontrol plate body, and the at least a portion of the valve controlplate is a valve seat insert that fills the trepanned groove.
 23. Thecontrol valve of claim 22, wherein the valve seat insert is molded intothe trepanned groove.
 24. The control valve of claim 23, wherein thevalve seat insert is retained in the trepanned groove by at least one ofposts, columns, and bridges.